I second nycindie's suggestion of reading Opening up - really, I think you should be reading LOTS of books, partially because you said "The options on that are: Poly relationship until I calm down, or I convince myself that there's no reason to ever want to sleep with anyone else.
Originally Posted by onoma
I want kids. I'm just not sure I want them next year. BUT, here's where the poly thing is coming in: If I had kids next year, and could still sleep with a few other women I'd be more comfortable with it.
It sounds to me like you don't even know if poly is what you'd want - I don't see being poly as - I'm going to find other people to sleep with until I decide there is no reason to keep sleeping with anybody but the mother of my kids. Nothing wrong if you just want an open relationship where you can be having sex, but be clear about what it is you're looking for. It seems to me like you are focused more on being able to have new sex partners than an urge to be able to have new RELATIONSHIPS. It sounds like what your girlfriend has suggested earlier was giving the former an attempt, but not the latter. Seems like you two still have lots of work on being clear about what you are hoping for.
I don't think that deciding you will have kids with her as long as you are able to be sleeping with other people really makes sense as a basis to stay together, and I'd recommend at least a year of being actively & HEALTHILY poly before even considering having children. I hope the time you're taking to work on your relationship now pays off!